Mill for crushing and grinding.



No. 834,381.v l

. G.. o. LITTLE.

MILL FOR @RUSHING AND GRINDING'.

APPLICATION FILED DEO. 19, 1904.

3 SHEETS-SHEET 1.

PATBNTED 00T. so, 190e. l

l Nofaaiaav. v PATENTED 00130, 1906.

G. C. LITTLE. AMILL FOR GRUSHING AND GRINDING.

APPLICATION FILED DEU. 19. 19,04.

3 SHEETS-SHEET 2.

, nient of the rotating wheels on the pan.

UNITED STATES GEORGE C. LITTLE, JAMESTOWN, NEW YORK.

vMILL FOR CRUSHING AND GRINDING.

i Specification of Letters Patent.

Patented oct. 3o, 190e.

Application led December 19, 1904. Serial No. 237,354.

y,To @ZZ whom it may concern,.-

.and State of New York, have invented a new and useful Mill for Crushingand Grinding, of which the following, taken in connection with theaccompanying drawings, 'is a full, clear, and exact description.

My invention relates to millstones, particularly to the form ofcrushing-mill known as the Chilian mill, which consists of a revolvingpan and two heavy wheels or rollers mounted on a horizontal shaft. Thewheels travel in the revolving pan, with scrapers to keep the materialin the path of the wheels. This form of mill is often called a dry orwet pan, according to the condition of the material ground.

The object of my improvement is to form a combined crushing and grindingmill by providing an unyielding means for holding the angle of the axlesof both of thek wheels or rollers off the radius or tangent ofthe circleof their revolution in the pan, so that the pan will have a continuousoutward slipping vmovement on the periphery of the wheels,

and to provide. heavy hubs, buffer-locks, and a frame to withstand thestrong outwardv thrust consequent upon the macerating action or forceofthe outward or off angle movt isexperimentally found that the amountof resistance on the working faces of the pan andgwheels when the wheelsare placed back of and oif the radius of the pan in respect to directionof pan rotation is practically in proportion to the amount of executionor grinding efciency of the mill, and my improved arrangement of thewheels not only doubles and trebles the capacity of the mill, accordingto the diHerent materials to be ground, but also enables me to grindsubstances which the old form of mill could not grind. The unyieldinnature of this construction, .combined wit the crushing and grindingmovement, y forms a macerating action which enables the mill towithstand the shock of large rocks and to pulverize the hardestsubstances, such as white flint, glass, vitried brick, and the like.

Inv the drawings, Figure 1 is a lan view, partlyv in section, of thepan, w eels, and frame as I usually arrange them, the upper portion ofthe frame being cut awayto reveal the improved arrangement of the wheelsand their shaft. Fic'. 2 is a sectional view of the central hub or c ampfor the horizontal shaft or double axle at line X yX in Fig. 1. Fig. 3is a detail view of the squared outer end of the horizontal shaft andbuiier, the latter being in section. Fig. 4 is a modification of thehorizontal shaft or axle for the wheels without the central adjustinghubor clamp. Fig. 5 is a perspective view of the complete mill. Fig. 6 is aplan view of a modification of my improved placing of the wheels withthe upper portion of the frame cut away, as in Fig. 1. Fig. 7 is asectional view of the pan and frame and a side elevation of thegrinding-wheels and shaft in an angular position caused by a large stoneunder one of the wheels. -One of the parts of l the central hub and theshim-blocks of one side are removed to show the openin in the center ofthe hub around the vertica shaft. Fig. 8 is a chart of the pan, showingthe grinding-wheels at different degrees of angular displacement.

Similar characters refer to corresponding parts in the several views.

' The numeral 10 indicates the frame, which is made with sufficientweight and strength to withstand the great outward strain of themacerating mill-wheels. Guide-pieces 11, of angle-iron, are bolted tothe inner side of frame 10in a vertical position to form vertical guidesin which buffer-blocks 12 13 slide, the -portion 12 of the blocksextending in between the guides 11 and the portion 13 bearing upon theedges of the guides. The part 12 does not extend to frame 10, andinconsequence the guides 1 1 sustain the whole weight and wear of theoutward strain on the buffer-blocks. This arrangement preserves theframe-piece 10 from wear, and the guidepieces 11 are easily renewablewhenever they become worn. The bearing of the bufferblocks on the guidesshould` be broad and strong, so as to withstand any amount of shock. v

A horizontal shaft or axle 16 is slidably mounted in buffer-blocks 12 13and held rigas they bear against lock 13. In order to IIO obtain therearward placing of the wheels from the radius, a central divergence orbend is necessary in shaft 16. This might be obtained by a bend as shownin Fig. 4; but T preferably make the shaft 16 in two parts and connectthe inner ends by a central yoke or clamp 17, which extends with an openspace 36 around the vertical shaft 18 in order to allow for the raisingof either end of the shaft and yet preserve a stiif shaft which will notbend or spring between the two wheels which are mounted thereon.

A pan 20 is mounted on a vertical shaft 18 and revolved thereby and hasan inner diskshaped portion 21, which is formed of hea'vy renewablelates made of hardened metal, upon whicii the heavy grinding-wheels 15bear. For a dry or semidry pan a grating or screen portion 22 isarranged around central portion 21, over which the material is thrown bycentrifugal force, and through this screen it drops when sufliciently puverized, and from which it is carried away by suitable conveyers. fetpans are used for preparing plastic material, and in their constructionthe screen-plates 22 are dispensed with. My improvement is equallyapplicable to dry or wet pans. Scrapers 23, supported on crossrods 24,serve to keep the material in the path of the wheels 15. Scrapers 23have points 25 at their outer ends to scrape the material from the innerside of the upturned edge of pan 20, as the material is caused to adhereto the said edge by the centrifugal force of the rapidly-revolved pan.Pan 20 is supported on shaft 18, and shaft 18 is revolubly stepped in abase 26 at its lower end and has its upper end supported in a cross-beam27 of the frame 10 and supports on its upper end the large bevel-gear28, which meshes in a gear 29 on driving-shaft 30, which is revolublymounted. in suitable boxes 31. on frame 10. The revolution of shaft 30is 4controlled by means of lever 32, which operates a friction-pulley 33to stop and start.

In the ordinary tangential arrangement of the grinding-wheels there isvery little slip or macerating movement, whereas in the nonradiallocation the pan slips on all parts of the periphery of the wheels, moreor less, dependent upon the degree of angular displacement of thewheel-axes and pan radius. The word slip as above used means to move incontinuous contact without rolling, the pan slipping on the periphery ofthe wheels. The non-radial placing of the wheels in the pan causes acombined slipping and rolling movement between the two. The wheels turnon their shaft as the friction of the revolving pan is applied to them,and the pan, because of the displacement of the wheels, slips or isdrawn beneath the surface of the heavy ofllaced wheels. Thus in Fig. 8,with the w eel. A having its axis on the tendegree line behind radius YY, the pan turning in the direction shown by the arrows will slip aboutone-tenth of the circumference of the wheel. Titb the wheel B having itsaxis at the forty-iive-degree point behind radius Y Y the pan will slipone-half and the wheel will rotate one-half of said circumference. Thelimiting position is given by wheel C in its right-angle position toradius Y Y on the ninetydegree line, in which position the wheel wouldnot turn on its axis at all, but the pan would simply drag under thestationary` wheel. It is immaterial how wheel C reaches the limitingposition on the ninetydegree line, whether through one quadrant or theother or forward or backward in respect to the direction of panrotation. The result is the same, and the wheel will drag.

It is obvious that a rotatable wheel driven by the friction of arevolving pan will have an outward throw at any point between that ofwheel C on the ninety-degree line and radius Y Y in the quadrant inwhich wheel A is placed and that as the line Y Yis passed from saidquadrant the wheel will have an opposite or inward throw at any pointuntil the other ninety degree line is reached. Thus, for example, in Fig. 1 the axes of the wheels 15 are shown by the points B B and theradius of the pan by the line C C through the vertical axis A. Thewheels 15 therefore are in the rearward quadrants as to radius C C, andhence have an outward motion with the pan revolving in the directionshown by the arrows. Should the wheels 15, however, be placed forward ofline C in respect to direction of'pan rotation, said wheels would havean inward tendency, and the ,crushing and macerating action would belargely destroyed. The wheels would rua much easier and would hug theinner washer on the shaft, thus needing no provision for outward thrust,as in my placing of the wheels. This inward movement seems to equalizethe run of the wheels, and they have almost no macerating slip. The4rearward placing with outward throw is necessary in order to obtainthis positive slip. 1 vary this rearward placing of shaft 16 at theinner end by means of shim-blocks 34 and on the outer end by thecorresponding sidewise shifting of the sliding-ways 11 by means ofsuitable bolt-holes 37 in frame 1.0. Shimblocks 34 are made with asemicircular opening and extension 35 on opposite sides to iit the innerfaces of the parts 17 of the central yoke, so as to clamp shaft 16therein and at the same time hold the shim-blocks in place. It isapparent that hub or clamp 17 can be enlarged to any desired degree, theopening 36 around vertical shaft 1S being changed from a circular to anelliptical form by the insertion of the shim-blocks.

In order to crush and Orind large pieces of rock and like material, thestiil unbendable mounting of the single horizontal shaft 16 17 lOO IlO

for both'wheels is anecessity. The quartering' blow oflarge pieces ofrock upon the angularlydisplaced wheel and the impetus given by therapidly-revolving pan are so great that any resiliency or spring in themounting ofy shaft 16 17 for wheels 15 wouldthrow them out onto thelight screen-plates 22, as will readily be appreciated by a glance atFig. 7, wherein the rock has thrown the wheelfhigh in the air, and ifthev wheel did not have `the heavy buHer-block 13l tostrike against,guidepieces 11, and heavy central yoke 17 to withstand the shock andhold the wheels parallel, the bottom of the wheel would be thrown outonto the screen-plate, breaking the same. By the unyielding heavycentral yoke, on which a lheavy breaking strain falls, the wheel isgiven a firm tension. The bufferblocks hold the wheels steadily andfirmlv to.

their work of maceration, and the wheel comes down ontothe central disk21 with added crushing force .by being held firmly to its work. Itstrikes the plate not only with a downward blow, but with a sideslipfrom the pan that is irresistible. Thev shaft of wheel 15 must beunyielding as against this strain, however, and the wheel lmust notwabble or give in any way as it strikes the rock, asshown in Fig. 7, andit is experimentally found that this macerat'ing shock breaks thehardest flint cobble-stones and other like substances, grinding them topowder. It is also found that the provision of short individual shaftswith separate mounting for each wheel produces a construction which itis impossible to control by any known mechanism'as against such a blow.It must4 bev borne in mind that vmy mill is for both crushing andgrinding. My arrangement forces the heavy wheels to perform bothoffices.v When it is understood that these grinding-wheels 15 weigh fromone to ten tons each, the reatimportance of my unyielding'yoke and shaftconstruction will be appreclated.

In operating the mill the pan 20 is turned by means of vertical shaft18, gears 28 and 29, shaft 30, and pulley 33, as above described. Therevolution of the pan with the frictionl of the material to be groundcauses the rotation of wheels 15 on shafts 16 as they bear upon it. vItis experimentally found, however, that with my improved placingl ofwheels 15 ak reduced amount even of coarse material canbe worked inthepan, thereby vrunning easier ythan the old way and pulvertheirpulverizing power, since the pan and wheels are brought more closely anduniformly io. contact.

It is apparent that the two parts of they horizontal shaft 16 areparallel to the same diametral line, as C C in Fig. 1,v of the pan andto each other, though placed in the staggered arrangement. In themodification shown in Fig. 4 this parallel arrangement of shafts16`showsthat though the parts are changed somewhat .to allowvfor theangular 'placing of the shafts, yet the shafts vthemselves arevertically parallel and if a rhomboidal form of frame ,were provided thearrangement would be exactly the same as in Fig. 1. gularplacing ofshafts 1.6 tothe square form of frame 10, the o enings in buffer-blocks13 are madeat the esired angle and the faces of buffers 13 next to thehubs 14 are made at corresponding angles, so that the wheels 15 areturned at an off angle the same a's they would be if,placed forwardofthe radius of the circle of revolution, as shown in Fig. 1. Themodification shown in Fig. 4 would attain my purpose, but is not as wellbalanced as clamp 17.

I claim as new- 1. In a machine for crushing and grinding, a suitablepan and means for turning the same, vertical ways above said pan, asingle horizontal shaft having its ends slidabl mounted in said ways, apair of vertical mil wheels revolubly and shdably mounted on said shaftto the rear of and off the radius of said pan in respect to itsdirection of rotation, and unyie ding buffer-blocks outside of saidwheels to resist the outward pressure of said off-placed wheels.

2. In a machine for crushing and grinding, a suitable pan and means forturning the same, vertical ways above said pan, a horizontal shafthaving a central divergence therein and its ends slidably mounted insaid ways, vertical mill-wheels revolubly mounted on said shaft to therear of and off the radius of said pan in respect to its direction ofrotation by said diver ence, and unyielding buffer-blocks on said s aftto resist the outward ressure of said off-placed wheels.

3. n a mill for crushing and grinding, a frame, a pan in said frame on avertical shaft and means for turning the same, vertical ways on saidframe above said pan, bufferblocks slidably mounted on said ways, ahori-In order, however, to adapt the an- IOO vzo

zontal shaft rigidly mounted in said blocks to revent turning, verticalmill-wheels revolulhly mounted on said shaft to bear against saidblocks, and a central divergence in said horizontal shaft placing itsends behind and off the radius of said pan with respect to its directionof rotation.

4. In a mill for crushing and grinding, a frame, a pan in said frame ona vertical shaft and-means for turning the same, a horizontal shaftabove said pan composed of parts having their outer endssupported onsaid i'rame with freedom of vertical movement, a clamping-yoke for theinner ends of said parts, said parts of shaft mounted respectivelybehind and ofi the radius of said pan with respect to its direction ofrotation, vertical mill-wheels revolubly mounted on said parts of shaft,and unyielding means for controlling the resulting outward motion ofthewheels.

5. In a mill for crushing and grinding, a frame, a pan in said frame ona vertical shaft and means for turning the same, adjustable verticalways on the opposite inner sides of said iframe, buffer-blocks slidablymounted in said ways, a rigid horizontal shaft composed of two partsmounted at the outer ends in said blocks to prevent turning, a clampingyoke having divergent openings on opposite sides for the inner ends ofsaid parts and arranged to receive spreading shim-blocks, and

vertical mill-wheels revolubly mounted on said parts of shaft to therear of and oif the radius of said pan in respect to its direction ofrotation and bearing against said blocks, substantially as and for thepurpose specified.

6. In a mill for crushing and grinding, a frame 10, a pan 20 revolublymounted on shaft 18 in said frame and means for turning the same,adjustable vertical ways 11 on the opposite inner sides of said frame,bufferblocks 13 slidably bearing on and in said ways, an unyieldinghorizontal shaft composed of parts having their outer ends mounted insaid blocks to prevent turning and a divergent clamping-yoke 17 for theinner ends of said parts of shaft, an opening 36 for shaft 18 in yoke17, shim-blocks 34 to spread the parts of yokes 17, and verticalmill-wheels 15 revolubly mounted on shaft 16 to the rear of and oif theradius of their rotation in said an in respect to its direction ofrotation and bearing against said blocks, substantially as and for thepurpose specified.

In testimony whereof I have signed my name to this specification in thepresence of' two subscribing witnesses.

GEORGE C. LITTLE.

Witnesses:

A. L. FURLow, S. A. BALDWIN.

